Method for the manufacture of concrete pipe fittings

ABSTRACT

THE PRESENT DISCLOSURE PERTAINS TO AN AUTOMATIC DRAIN TILE MAKING MACHINE WHICH EMPLOYS VERTICALLY RECIPROCAL PACKER HEADS AND PUSH-RODS TO FORM A TILE WITHIN A MOLD AND TO EJECT THE FORMED TILE ONTO A PALLET BY AXIALLY MOVING THE PUSH-RODS THROUGH THE MOLD. THE MACHINE IS PROVIDED WITH A PLURALITY OF MOLDS WHICH ARE FIXED TO A TURNTABLE SO AS TO PERMIT SIMULTANEOUS MOLDING AND EJEC-   TION DURING EACH VERTICAL CYCLE OF A HEAD WHCIH CARRIES THE PACKER HEADS AND PUSH-RODS.

April 13, 1971 G. F. RUEGSEGGER 3,574,817

METHOD FOR THE MANUFACTURE OF CONCRETE PIPE FITTINGS Original Filed May 9, 1967 v b/mfar @ejseyyef JE?? @j Unlted States Patent Oihce 3,574,817 Patented Apr. 13, 1971 ABSTRACT OF THE DISCLOSURE The present disclosure pertains to an automatic drain tile making machine which employs vertically reciprocal packer heads and push-rods to form a tile within a mold and to eject the formed tile onto a pallet by axially moving the push-rods through the mold. The machine is provided with a plurality of molds which are xed to a turntable so as to permit simultaneous molding and ejection during each vertical cycle of a head which carries the packer heads and push-rods.

This invention relates to the method for automatically producing concrete pipes which have one end shaped irregularly so as to adapt the pipes for assembly into T, L or similar sections.

The molds employed are of regular cylindrical shape and are capable of producing concrete pipes of regular square-ended contour. The irregular contour at one end of the pipes is obtained by providing an insert in the top portion of the mold during the molding operaton. The insert is cylindrical in its end view and is of equal wall thickness as the intended tile. Its top edge is even and square to the axis of the mold; however, its lower edge is contoured to complement the desired end contour of the pipe to .be produced. Because of the insert, the tile which is formed by the packer head in a known manner will have an irregular contour as described above.

An electro-magnet which is provided at the mold sidewall releasably maintains the insert in the upper mold position during the molding operation and during rotation of the turntable. In ejecting the tile, the push-rod moves against the top edge of the insert at which time the rst electro-magnet is deenergized and a second electromagnet, provided in the lower face of the push-rod, takes over. As the push-rod progresses downwardly the insert moves with it and in turn pushes the formed tile onto a pallet. On the return stroke the push-rod carries the insert back to its original position at which point the second electro-magnet is deenergized and the iirst magnet is energized to retain the insert in its original position.

RELATED APPLICATIONS This application for a patent is a divisional application of my application S.N. 637,170, entitled, Machine for Manufacturing Concrete Pipe Fittings, filed on May 9, 1967, and now patent No. 3,500,514. This application is colpending with my application entitled, Machine for Making Concrete Pipes, Ser. No. 637,190, showing the automatic tile making machine for which the disclosed mold and apparatus is particularly designed.

BACKGROUND OF THE INVENTION The field of invention encompasses concrete pipe making machines and particularly machines for making concrete pipe T, L and other types of irregular sections.

The prior art in this field consists of either complicated and specially designed molds for producing concrete pipes with irregular end sections, or it merely consists of the method of producing regular square ended pipes and subsequently sawing one end of the pipes to the desired contour.

SUMMARY The principal object of the present invention is to provide a mold design which will be Well suited for the production of ordinary concrete pipe as well as for the production of concrete pipe having an irregularly shaped end.

The heart of the invention resides in the provision of an insert within the mold and of a mechanism which will be capable of maintaining the insert at the top of the mold during the molding operation and of permitting the insert to reciprocate within the mold during the ejection of the tile from the mold.

DESCRIPTION OF DRAWINGS Other objects and advantages will be pointed out in, or be apparent from the description and claim, as will obvious modifications of the embodiment shown in the drawings, in which:

FIG. 1 is a perspective view of the tile molding machine employing the present invention;

FIG. 2 is a cross-sectional view of a mold containing the insert and being positioned underneath a push-out rod;

FIG. 3 is a cross-sectional View of the mold with the parts being shown as required during the molding operation;

FIG. 4 is a similar cross-sectional -view with the parts being shown at the start of the ejection cycle;

FIG. 5 is a similar view showing the parts at the lowermost position of the cycle; and

FIG. 6 shows various sections which can be manufacturedby the molding machine and process embodying the present invention.

The illustrated mold is designed for use in an automatic drain tile making machine as shown in FIG. l. 'Ihe machine has a vertically movable head frame 10 which carries one or more packer heads 12 and push-out rods 14. As the head descends from its uppermost position the packer heads enter one set of molds 16 to form drain tile in the known manner of inserting the heads adjacent the bottoms of the molds, conveying concrete pipe formingr material to the molds, and withdrawing the packer heads upwardly through the molds. The push-out rods enter the other sets of molds 16 to eject the molds onto a pallet which is carried by arms 18 which are xed to the head frame. At the lowermost position the loaded pallet is deposited upon a conveyor and on the upstroke an empty pallet is picked up by the arms. As the head frame reaches its uppermost position the tile in molds 16 is fully formed and thereafter the turntable 19 is moved through 180 whereafter the above-described cycle is repeated.

The operation described so far can produce regular tile lhaving both ends square to the axis of the tile.

iIn order to provide a tile which may be used to form an L joint, one end of the tile must be at 45 to the axis of the tile. In order to produce such tile an insert 20 is removably placed within the mold 16 `and is maintained in the upper position of the mold, as shown in FIG. 3, during the cycle in which the packer head forms a tile within the mold. Since the insert is equal in thickness to the tile 22, the top edge 23 of the tile will assume a contour complementary to the bottom contour 23 of the insert.

The insert is preferably made of brass and it has smooth inside and outside sidewalls so as to permit easy movement within the mold and so as to avoid any accumulation of concrete. It is provided with a metallic magnetizable insert 24 which is in alignment with an electro-magnet 25 xed to the sidewall of the mold 16.

The magnet 25 is energized during the molding cycle and has a sufficient eld to maintain the insert xed during this cycle. It is also energized during the 180 movement of the turntable to thereby prevent the weight of the insert from exerting a downward force on the tile.

When the mold has been moved in alignment with the push-out rod 14, the latter moves downwardly and comes in contact with the top edge of the insert. At this time a control circuit (FIG. 4) deenergizes the magnet 25 and energizes an electro-magnet 26 provided on the lower face of the push-out rod. The magnet 26 has a sufficient dield to hold the insert which is provided with a metallic magnetizable section 27 on its top edge. As the push-out rod progresses downwardly the insert pushes against the freshly formed tile to guide it onto the pallet in a known manner. After the tile has been fully ejected the push-out rod moves upwardly and carries the insert to its original position within the mold. At this point the magnet 26 is deenergized and magnet 25 is energized to thereby again fix the insert in a proper position for forming the next tile of a contour as described. At this point the turntable is again turned through 180 and the cycle is repeated.

A suitable control circuit is shown in FIG. 4. rIhe circuit contains a double acting snap action switch 28 which is normally biased to close on contact 29 and thereby energize the coil of the electro-magnet 25. The switch can be actuated in response to the movement of push-out rod 14 by any convenient connection (schematically shown by broken line 30) so that the switch snaps to close on contact 31 when the push-out rod moves downwardly to a position adjacent to the insert to thereby energize the coil of electro-magnet 26 and simultaneously deenergizing the coil of electro-magnet 2S. The switch remains in this position until the end of the reciprocal movement of the push-out rod and it snaps from contact 31 to contact 29 as t-he push-out rod leaves the mold to thereby again energize the coil of electro-magnet and deenergize electro-magnet 26.

Although the illustrated embodiment pertains to an insert which will provide a 45 end face to the formed tile, it is apparent that by providing inserts having diiferently shaped lower edges various concrete pipe sections may be produced.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modications may be made therein without departing from the spirit of the invention or from the scope of the appended c alm.

I claim:

1. A method for molding a concrete pipe of the type having an axially irregular contoured end in a machine in which the pipe is formed in a generally cylindrical mold by a pipe forming tool which enters the top end of the mold and in which the formed pipe is removed by a push-out means which is inserted into said top end of the mold after removal of the pipe forming tool and which pushes the formed pipe out of the mold, the method being comprised of lthe following steps:

(l) releasably securing an annular insert concentrically inside of the mold at its top end, with the bottom edge of said insert being contoured to complement the axially irregular contoured end of the pipe to be formed and with said insert Lhaving a wall thickness substantially equal to the wall thickness of the pipe to be formed;

(2) inserting a pipe forming tool adjacent the bottom of said mold and conveying pipe forming material to said mold and withdrawing said tool upwardly through said mold and said insert to form a pipe, said pipe being formed at the sidewalls of said mold and terminating at the bottom edge of said insert;

(3) moving push-out means towards the top end of said mold and disengaging said annular insert from said mold while releasably securing said insert to the said push-out means;

(4) moving said push-out means and said secured insert into said mold to thereby push the formed pipe out through the bottom end of said mold;

(5) moving said push-out means and said secured insert back towards said top end of said mold; and

(6) releasing said insert from said push-out means and simultaneously securing said insert to said mold at the top end of the mold as said push-out means is removed from said mold to thereby render said mold in condition for forming of another pipe.

References Cited UNITED STATES PATENTS 1,372,861 3/1921 Birdsey 264--336 3,078,539 2/1963 Duplessis 25-1120X 3,273,216 9/1966 Gourlie 25-36X FOREIGN PATENTS 153,944 1/1952 Australia 25-36 ROBERT T. WHITE, Primary Examiner A. M. SOKAL, Assistant Examiner 

